Railway trappi-c controlling apparatus



March 8, 1932. R. M. GILSON ET AL RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Nov. 1'7, 1930 INVENTORS RJW, Gf/son, A4 H.P 7'ho 0n,'

V-ZWA ATTORNEY Patented Mar. 8, 1932 UETED STATES PATENT OFFICE ROBERT M. GILSON, OF PITTSBURGH, AND HOWARD A. THOMPSON, OF EDGEWOOD, PENNSYLVANIA, ASSIGNORS TO THE UNION SWITCH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA RAILWAY TRAFFIC CONTROLLING APPARATUS Application filed November 17, 1930. Serial No. 496,100.

Our invention relates to railway traffic controlling apparatus, and particularly to automatic train control or cab signal systems of the continuous inductive type. More specifically our present invention relates to the trackway portions of such systems.

We will describe one form of trackway apparatus embodying ourinvention, and will then point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic view showing one form of trackway apparatus embodying our invention.

Referring to the drawing, the reference characters 1 and 1 designate the track rails of a stretch of electric railway track along which trafiic normally moves in the direction indicated by the arrow. These rails are divided by insulated joints 2, to form a plurality of track sections, of which only one section CD is shown in the drawing, and the usual impedance bonds 18 are provided to conduct the propulsion current around the insulated joints.

Located adjacent the entrance] end of section GD, isa track relay E which, as here shown, is of the centrifugal type; This relay comprises a rotor 3, two stator windings 4 and 5, a centrifugal device 6 operated by the rotor 3, and a contact 7 which is closed when and only when the centrifugal device is rotating at or above a given speed. The stator Winding 4 is connected across the trackrails 1 and 1 and the other stator winding 5 is at times energized as hereinafter explained.

Located adjacent the exit end of the track section GD is a track transformer F, the secondary 8 of which is connectedacross the track rails, and the primary 9 of which is at times energized as hereinafter explained.

The track relay E controls a coding relay G in such manner that the coding relay is energized whenand only when front contact 7 of relay E is closed. The circuit for the relay G is from terminal B of a suitable source of current, through contact 7 of relay E and the winding of relay G to terminal 0 of the same source of current.

The coding relay G controls a coding device H, which device comprises an operating winding 14, and two contacts 15 and 16 which are periodically closed at different rates when the winding 14 is energized. The circuit for winding 14 of the coding device H is from terminal B, through back contact 12 of relay G, and the winding 14 to terminal 0. It follows that the coding device H is normally deenergized, but is set into operation whenthe coding relay G becomes deenergized.

When the coding relay G is energized, the primary 9 of transformer F and the stator winding 5 of relay E are both supplied with uninterrupted alternating current of a given voltage, such, for example, as 110 volts. The circuit for the transformer primary is from terminal X110 of a suitable source of alternating current, through the front point of contact 10 of relay G, and the primary 9 of transformer F to terminal YllO of the same source of current. The circuit for relay winding 5 is from terminal X110, through front point of contact 11 of relay G, and the winding 5 to terminal YllO.

When relay G becomes deenergized, the circuits just traced for the primary 9 of transformer F and the Winding 5 of relay E will he opened at front points of contacts 10 and 11, and new circuits for these elements will become closed at the back points of the same contacts, which circuits are supplied with energy from an auto-transformer K. The primary circuit for auto-transformer K is from terminal X110, through contact 15 or 16 of the coding device H, front or back point of contact 17 of relay E for the section in advance of section CD, back contact 13 of relay G, and the winding of auto-transformer K to terminal Y110.

The circuit for the primary 9 of track transformer F will then be from terminal 18 of transformer K, through the back point of contact 10 of relay G, and the primary 9 of transformer F to terminal Y110. The voltage which will thus be applied to transformer primary 9 will be considerably less than 110 volts, and may, for example, be about volts. Furthermore, it will be periodically interrupted at one rate or an other by contact 15 or 16 of the coding device tion in advance of section CD is unoccupied or occupied; The new circuit for winding 5 of relay E will be from terminal 1.9'oi' transformer Kthrough the point of contact 11 of'relay G, and Winding 5 to terminal YllO. The voltage which is thus applied to winding 5 willbe considerably less than llOrvolts, and may for example, be 65 volts. The currentsupplied.

to this winding will, of course, be periodically interrupted in synchrcnism with the current supplied'to primary 9 of transformer F.

When the train passes: out of section (1-D, track relay E will again become energized, thereby closing contact? so'that relay G will become energized. Uninterrupted alternating current: of 110 volts will again be supplied to transformer primary 9 and track relay winding 5, so that the apparatus will be restored'to the conditon in which it is shown in the drawing. 7 s

'Heretofore, in systems of this character, it has been customary to supply'uninterrupted alternating current at 110 volts to primary 9 and track relay winding 5 when the section is unoccupied, and tosupply periodically interrupted current at 110 volts to these elements when the section is occupied by a train.

- We have found-thatunder these conditions thetrain-carried apparatus which responds to the periodically interrupted or coded current in the track ra1ls may be energlzed to an excessive-value, and we have also found that this over-energization reduces the sensitivity of the apparatus in sofar as concerns the detecting of a broken rail. That is to say, shouldone of the rails ofsection C'-D be broken, he so-called sneak currents through the impedance bonds, the crossbondin'g between rails, and the unbroken rail may be suflicient to falsely energize the-train-carried apparatus. In accordance with our invention, the amount of current supplied to the track rails by the transformer F when the section is occupied, isreduced to such value that it will satisfactorily operate the train-carried apparatus under normal conditions,- but that in theevent of a broken rail the-snealrcurrents will not be of sufficient value to falselyenergize the apparatus on the train. 1

will be noted that track transformer F' and track relay winding 5 are normally supfectively energized at substantially one-halfof the normal operating voltage, but that when energlzed at such" voltages they are ex tremely slow to release their front contacts in response to the shunting of the track winding 4 when a train enters the section. When the relay is energized at normal voltage, however, the release of the front contacts in re sponse to the shunting by a train is greatly expedited. In accordance with our invention, therefore, we are able to insure broken rail protection by 10w energylevel when the track section is occupied, without sacrificing the quick shunting of the track relay when a train enters the section.

l/Vhen relays of'other types are used, the same result may be attained by reducing the track voltage below normal when the section is occupied, and at the same time increasing the voltage applied to the local winding of the relayto such amount as to insure that the relay will-pickup when the train leaves the section.

Although we have herein shown and described only one form of apparatus embodying our invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit. and scope of our invention;

Having thus described our invention, what we claim is: I

I. In a combination, a section of railway track-a centrifugal track relay for said section having two windings 'thefirst of which is connected across the rails of the section, a

normallyenergized approach relay having a circuit controlled by a front contact of said track relay, a normally deenergized coding device set into operation'when said approach relay becomes deenergized, means operating; when said aproach relay is energized to supply uninterrupted alternating currents to the rails of said'section and'to the secondwinding of said track relay, and means operatingwhen said approach relay is deenergized' and said coding device 1s in operation to supply periodically interrupted alternating currents at lower voltages to the-rails of said section and to the second winding of said track relay.

2. In combination, a section of railway traclr,'a centrifugal track relay for said section having two "windings the first of which is connected across the rails of the section, a normally deenergized coding device set into operation when said track relay becomes deenergized, means operating when said track relay'is energized to supply uninterrupted alternating currents to the rails of said section and to the second winding of said track relay, and means operating when said track relay is deenergized and said coding device is in operation to supply periodically interrupted alternating currentsat lower voltages to the rails of said section and to the second winding of said track relay. c

3. In combination, a section of railway track, a centrifugal track relay for said section having two windings the first of which is connected across the rails of the section, means operating when said track relay is energized to supply uninterrupted alternating currents to the rails of said section and to the second winding of the track relay, and means operating when the track relay is deenergized to supply periodically interrupted alternating currents at lower voltages to the rails of said section and to the second winding of the track relay.

4. In combination, a section of railway track, a track relay for said section having two windings the first of which is connected across the rails of the section, means operating when said track relay is energized to supply uninterrupted alternating currents to the rails of said section and to the second winding of the track relay, and means operating when the track relay is deenergized to supply periodically interrupted alternating currents at lower voltages to the rails of said section and to the second winding of the track relay.

5. In combination, a section of railway track, a track relay having a winding connected across the rails of said section, means operating when said relay is energized to supply current at one voltage across the rails of said section through conductors independent of the conductors by which said relay winding is connected with the rails, and means responding to the deenergization of said relay to reduce the voltage of the current supplied to the rails of said section.

6. In combination, a section of railway track, a track relay having a winding connected with the rails of said section, means operating when said relay is energized to supply uninterrupted alternating current at one voltage to the rails of said section, and means responding to the deenergization of said relay to supply periodically interrupted alternating currentat a lower voltage to the rails of said section.

7. In combination, a section of railway track, a centrifugal track relay for said section having two windings the first of which is connected across the rails of the section, means operating when said relay is energized to supply alternating currents at normal voltages to the rails of said section and to the second winding of the relay, and means responding to deenergization of said relay to reduce the voltages of the currents supplied to said rails and to said second winding.

8. In combination, a section of railway track, a centrifugal track relay for said section having two windings the first of which is connected across the rails of the section, and means controlled by said relay for supplying to the rails of said section and to the second winding of the relay uninterrupted alternating currents at normal voltages or periodically interrupted alternating currents at reduced voltages according as the relay is energized or deenergized.

9. In combination, a section of railway track, a centrifugal track relay for said section having two windings the first of which is connected across the rails of the section, and means controlled by said relay for supplying alternating currents to the rails of said section and to the second winding of the relay at normal or reduced voltages according as the relay is energized or deenergized.

10. In combination, a section of railway track, a track relay having two windings the first of which is connected across the rails of said section, means operating when said relay is energized to supply uninterrupted alternating currents to the rails of said section and the second winding of said relay, and means operating when said relay is deenergized to supply periodically interrupted alternating current at reduced voltage to the rails of the section and periodically interrupted alternating current to the second relay winding at a voltage such that the relay will pick up when the section becomes unoccupied.

11. In a track circuit system, a section of railway track, a track relay of the type that releases quickly when shunted after it has been energized by a powerful current and which controls the supply of current to the track, means, set in operation by the shunting of the track relay, to supply to the track a current less powerful than that normally supplied but sufficiently powerful, nevertheless, to effectively energize the track relay after it has been shunted, and means, set in operation when the track relay has become energized by the less powerful current, to supply to the track a current of such powerful character as to enable said track relay to release quickly when next shunted.

12. In a track circuit system, a section of railway track, a track relay of the type that releases quickly when shunted after being energized by a powerful current and which controls the supply of current to the track, means, set in operation by the shunting of the track relay, to supply to the track a train control current of a character less powerful than that normallv supplied to the track but sufficiently powerful, nevertheless, to energize the track relay after a train has passed out of the section, and means, set in operation when the track relay has become energized by the train control current, to supply to the track a current of such powerful character as to enable said track relay to release quickly when next shunted.

13. In a track circuit system, a section of railway track, a track relay of the type that releases quickly when shunted after it has been energized by current of a given character and which controls the supply of current to the track, means, set in operation by the'shunting of the track relay, to supply to I the track a ourrent of a character diflerent from current of the given character but effective, nevertheless, to energize the track relayafter it has-beenshuntechand means, set in operation when the track relay has become energized by current of thesecond character, to supply to the track a. current of'the-given character to thereby enablesaid track relay to release quickly when next shunted;

14. In combination, a second of railway track, a track relay havlnga WlHdHl'g connected across-the rails at one end-of said section, nieans operating when said relay is en 5 ergized to supply current at one voltage across the rails at the other end ofsa-id section, and" means responsive to the de-ene1'g1zat1on' of said relay to reduce the oltage of the current supplied to the rails.

15. In combination, asection of railway track. a track relay having a winding conneeted across the rails at one end of said section, and means controlled by said relay for supplying the rails at the'other end of said section with current of one voltage or another according as the relay is energizedor de-energized; V

16. In combination, a section of railway track, a track relay'having a winding connected across the rails at one endof said section, and means controlled by said relay for s'uppl'ylngthe rails at the other end of said section with current of'highor low voltage according as the relay is energized or-de-ener' gized.

In testimony whereof we afiix our signatures. v I V v ROBERTA I. GILSON. HOWARD A. THOMPSON. 

